Helicopter



Nov. 19, 1946.

A. SERNA HELICOPTER Filed Jan. 27, 1944 2 Sheets-Sheet 1 Isnnentor fl/ex 5627770,

A. SERNA HELICOPTER Nov. 19, 1946.

Filed Jan. 27, 1944 2 Sheets-SheetZ Patented Nov. 19, 1946 UNITED STATES PATENT OFFICE HELICOPTER Alex Serna, Dearborn, Mich. Application January 27, 1944, Serial Nb. 519,335

13 Claims.

The present invention relates to improvements in aircraft and, more particularly, to sustentation and propulsion systems therefor.

The primary object of the invention is to provide an aircraft of the helicopter type in which the vertical lifting means or propellers may be slightly canted to coincide with the wing surface of the plane so that the aircraft may be used for horizontal flight after the desired altitude has been reached.

Another object of the invention is to provide an aircraft of the helicopter type in which the vertical lifting propellers may be canted or slightly tilted from their vertical axis 'so that one of the blades thereof may be received in a well formed in thelwing section of the plane and form a continuous plane surface with the other vane of the propeller projecting beyondthe wing section and thereby increasing the overall wing lift area of the plane during its normal hori- Another object of the invention is to provide an aircraft of the helicopter type having a novel and unique propulsion system in which both of the vertical lifting propellers are rotated by the propulsion system in such a manner as to cause the propellers to rotate in reverse order during the vertical lift and to permit the propellers to be tilted for horizontal flight so that the extended propeller blades will have substantially the same cross-sectional form as the wing section of the plane.

Another object of the invention is to provide means for locking the propellers within the recesses or wells in the wing section to prevent rotation and substantially lock the propeller to the wing section so that the propeller becomes in effect an integral part thereof.

Another object of the, invention is to provide an aircraft of the above-mentioned character with means for tilting the blades of the propeller so as to vary the pitch thereof in reverse order and thereby increase and decrease the lifting power-as well as being able to arrange the propeller blades so as to be maintained in co-eX- tensive relation with the wing section.

Another object of the invention is to provide an aircraft of the above-mentioned type with an indicator to record theposition of the vertical lift propellers so as to facilitate the tilting thereof into the well or recess in the wing sec- "tion when the plane is converted for horizontal Another objectof the inventionis to provide an aircraft of the above-mentioned type in which relatively short wing sections are employed with the upper surfaces recessed for reception of one of the blades of the lifting propellers and a depressible surf-ace adapted to be hinged into and out, of position to form a continuous upper wing surface of the plane when the vertical lifting propellers are employed for gaining altitude.

Other objects and advantages of theinvention will becomeapparent during thecourse of the following descripton of the accompanying drawings, wherein:

M Figure 1 is an enlarged top elevational'view of an aircraft embodying the invention, illus-' trating a portion of the fuselage broken away in order; to show the various'structural. features and details of the drive mechanism;

Figure 2 is a transverse cross-sectional view taken on line 22 in Figure 1 looking in the direction of the arrows and illustrating in detail the manner in which the vertical lifting propellers may be projected from the well surface ,of the wing section when the propellers are used for gaining altitude; w i Figure 3' is a vertical cross-sectional view taken on line 3-3 in Figure 2 looking in the direction of the arrows and illustrating therelative positions of the bladesof the propeller when the same are angled one to the other;

Figure 4 is a. diagonal cross-sectional view taken on line 4- in Figure 2 illustrating the hinge joint, for the recess cover of the wing section;

Figure 5 is a transverse cross sectional view similar to Figure 4 illustrating the manner in which one of the propeller blades is nested within the well or recess in the wing section during horizontal fight;

direction of the arrows and illustrating the control for the variable pitch propeller;

Figure 9 is a top plan view of an aircraft illustrating the vertical lift propellers on each side thereof and showing the direction in which the same are rotated;

tending through the bore 23.

Figure is a front elevational view of the invention showing the propellers in their tilted position for horizontal flight; and

Figure 11 is a front elevational view of an aircraft showing the propellers arranged for vertical lift.

In the drawings, wherein for the purpose of illustrating the invention like reference characters will be employed to designate like parts throughout, attention. is directed to: Figure 9 tors l in the conventional manner to. facilitate the steering of the plane when in flight. The

fuselage 5 is provided with a cowling it and nose- II for accommodating the propeller I12. The structure thus far described is typical of a conventional aircraft except that the wing sections 6 are formed relatively shorter (Figures 1', 2 and 9') A motor F3 is provided for rotating; the propeller l2 as is the usual custom.

The wing sections 6 are relatively short and terminate at the ends in housing portions M with the" lower wing surface" l5 terminating in the housing portion H! in a well-rounded surface "l fi toprovid'e a stream'-lih e'd contour'. Mounted in the housing portion I 4' is a pair of brackets I1 secured to the bottom wall of the wing surface I 5 by suitable nuts or bolts'an'd said brackets [ll are 'provided with trunnion bearings IQ for receiving'a yoke frame having trunnions 2| and 22: received in the bearings iii. The trunmen 22 is substantially larger than the trunnion {Hand is provided with a central bore 23 termihating in an enlarged'bor'e portion 24.. The yoke frame are provided with" an annular boss 25 havinga bore 26 for rotatably supporting the hollow shaft portion 21 of a propeller yoke 28 provided with oppositely disposed tubular portions 29'; The yoke frame 20' projects upwardly I through an opening 30" in the wing, surface 6 and said"opening communicates with a tapered opening 31 extending inwardly from the outer end of the wing surface to a point 32 adjacent the fuselage 5. The opening 3| terminates at its outer end in the opening 3!! which is greatly reduced in size so' as to permit the yoke frame i 20 to project thereth'rough (Figures 6. and 7), and yet provide an end wing portion or cover for the top of the housing 14.

Journal'le'd in the tubular portions 29 of the propeller hub yoke 28 is a pair of propeller blades 36 having. their shafts as at 31 arranged in opposed relation and provided on the ends there-- of with offset arms 38 having eccentric'ally positi'oned pins 39. Said pins 39 are received in a cross head 40 having opposed slots 4| for slidably accommodating the pins 39 and rotatably secured to said cross head 40 as by being swivelled, is a shaft 4-2 which extends downwardly through. an opening Min the tubular portion 21 of the propeller hub 28. The lower. end of the slide rod 42" is provided with a block 45' having a. slot 46 for receiving an eccentric pin 41 carried by the offset arm 48 of the rotary control shaft Mi ex- Mounted within the enlarged portion 2'4 of the bore 23 is the hub portion 59 of a propeller drive gear 5| having its teeth 52 in mesh with the teeth .53 of the gear 54 keyed to the tubular propeller hub 21'.

Positioned adjacent the trunnion brackets I1 is a bearing bracket 55 having a bearing bo s 56 4 for supporting the outer end of a drive shaft 51. The outer end of the drive shaft-51 is provided with a bevel gear 53 drivingly engaging the bevel gear 5| so as to rotate the propeller hub 21 about its axis. It is to be understood that the propeller, including the blades 36, may rotate independently of the control shaft 42 and that rotation of the shaft 51 will drive the propeller at a desired rate of speed. The inner end of the shaft 51 is connected toa stub shaft 59 rotatably iournalled in a gear housing: 6|) andasillustrated in Figures 1 and 2, the shaft 51 is connected with the stub shaft 59 by means of a universal connection 6|. A worm wheel 62 is secured to the stub shaft and is drivingly engaged by a worm 63 mounted on the end of a shaft 65 which is rotatably supported in the gear housing $41 by the bearing boss 66. The gear housing 60 is supported in the fuselage 5 by means of supporting legs til held in place by any suitable means. An extension 68 is formed on the power shaft, of the motor l3 and is provided with a clutch member 69' adapted to be drivingly engaged with a clutch member is on. the shaft 65. The clutch comprising the parts. 69. and it maybe normally held together by' a suitable spring mechanism and for the purpose of'separating such clutch parts, a lever H is fulcrumed on a support .12 formed integral with the motor l3' and said lever is provided with a yoke 13' for being received in a grooved collar 14. A link 15 connects the lever H to a bell crank operating lverlfipivoted as at H to the gear housing 60 and said. bell crank lever 16 is provided with a handle portion l8 to facilitate clutching and unclutch'i'ngz'of the motor shaft 68 with the stub shaft 59.

ing. propeller blades 3% are mounted on. the ends of each wing section. 6. and since the structure embodied in each propeller mechanism is identical a description of one will sufiice for both. By inspection of Figure 2 it will. be noted. that the control rods 83 are connected to opposite ends of. the rock shaft 84 so asto be: rockedin unison by means of a. handy lever 85 pivoted to the bracket 86. and connected to the rock lever. 84

by means of bevel. gears 86- and 81.

An extension 88 is formed on the trunnion frame 20 and said extension is provided with. a pin 39 upon which is rotatably mounted a control rod connection 90' for accommodating a reciprocating control rod 91. Each control rod has its inner end connected to the arms 92 formed on a rock shaft 93 which is rotatably supported between spaced arms 94 of a bracket 95 so that said rods 9| may operatein unison. A manual control lever 96. is pivoted to the upper end of the bracket 95 and is provided with abevel gear 91 in mesh with a bevel gear 98 secured to the rock shaft 93 to facilitate rotation of the same and thereby adjust or tiltthe trunnion frame 29 may be provided for covering the opening and forming a continuous lipper wing surface.

The

.cover '99 i hinged to a vbracket member I66 formed integral with the drive shaft supporting bracket 55 (Figure 4-) and, as indicated in Figure l 4, the hinged cover 99 is provided with hinge brackets IIII secured to oifsetportions rIllihofrthe bracket Hill by means of hinge pintles I03. The

.inner end of .each hingedcovenilll is connected to an actuator .lever tilt by :means of a relatively u;

short I link .i 55 and said actuator lever "I04 is piv- .otally mounted on a bracket I96 .sectuedio the ,fuselage as shown .in Figure -2. The opposite end encircles the-control -rod I I4 to normally hold the bolt I'm-projected so as-to-engage'the edge of the .hingedcoveril and hold the same in place.

Mounted on a projecting end portion of the stub shaft 59 journalled in the reduction gear housingtllh-a bevel gear II5 drivingly engaging a bevelgear .I:I6 secured to a shaft I-II-in a bearing bracket t3 and said bearing bracket is secured to the gear housing 65 by means of a supporting arm H9. The bearing bracket H8 is provided with adisc I20 and the shaft I I1 isprovided with a pointer I2I adapted to register and align with a projection 22 on the disc I253. It is noted-that the indicatorpointer l2! rotates-with the shaft 513 at the same speedthereof and the pointer is positioned so that when it is desired'to tilt the yoke 3.

frame 26 on its trunnion supports I9, the pilot may determine from the indicator the relative position of the propeller blades 1-36 shownby dotted lines in Figure 1 so that when the control lever 96 isroperated-to tilt the trunnion frame 20, the innermost propeller blade of each propeller will be guided through a partial rotation directly into the recess 3|.

.After the pilot has thus determined the location of the vpropeller blades 36, the control lever H2 for the latch Il -0 is operated to release the latch and permit the operation of the hand lever -I 9! so as to retract the hinged cover member 99 within the recess 3! as shown in Figure 2. After the propeller blades 36 are thusaligned withthe opening3l the may be lowered as indicated in dotted lines in Figure 2 so that the bolts ill] may be projected into an opening I25 in the end of each propeller blade 36. In this manner, the propellermay be held in position so that the outermost blade 36 will extend inalignment @withthe wing section .6 and form a continuation of the lift surface of the wing section. With the pmpellers thus nested, the propeller I2 may cause theplane to bepropelled in a horizontal flight as indicated in Figure .10. During landing or ascension, the propellers may be arranged as shown in'Figure 2 by operating the control lever .96 after which the control lever 85.15 shifted to angle the blades .36 of the propellers to give the required liftingeifect. When the propellers are left tilted or angled one :to the otherby operation'of the control lever 85, the clutch including the parts 469 and wmay-be engaged'byoperation of thelever T8. so as to drive the propellers and cause the same to be rotated for accomplishing a vertical lift as shown in Figure 11. When the propellers are thus arrangedas shown in Figure 2, thehinged covers-99 are.raise'd by the control-lever I01 and held in place by the detent IE8 engaging within the notch ,-in the sector plate I09. It is to be understood that during horizontal flight, the

propeller blades :35 will be rocked about their axes .31 so that the innermostblade'will benested in the opening .3I and with its surface faired into the adjacent wingsurface to-form an aerodynamic cross-sectional profile of the wing section in which it is nested, as shown in Figure 5, while the outermost bladewill extend beyond the wing section and likewise conform in cross section to the cross section of the wing section 6.

It is to be understood that the "aircraft above described may be converted from a helicopter type plane to a conventional-plane in a relatively short time so that after the desired altitude has been reached the conversion may be made quickly so as not to lose altitude upon cessation of operation-and rotation of the propellers 35. During the vertical flight the propeller I2 maybe rotated to cause a combined horizontaland-vertical lift with the wing section providing a portion of the vertical lift and the ailerons I26 adjusted accordingly for such combined forward and "vertical motion.

During the above-mentioned conversion, the area of the wingsection'fiissufficient to support the plane in horizontal flight. ,Also, the propeller 12 may be of the variable pitch type so as tocontrol the forward travel of the plane during sections and a propeller for horizontal flight, 21

Vertical lifting propeller mounted adjacent the end of each wing-section, means for rocking said vertical lifting propellers transversely of their :axes .froman operative position to a position of rest so that a portion 'of each lifting propeller :will be received "in a recess in its corresponding wing section with the remaining portionthereof extending beyond the wing section, and means for :rotating said propellers in reverse directions when in said operative position.

12. 'In combination'withan aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted on each wing section adjacent the end thereof for rotational and rocking-movement, means .for rocking said lifting propellers transversely of their axes from operative position to a position of rest so that aportion of each lifting propeller will bereceived ina recess .inits corresponding (wing section with the remaining portionrthereof extending beyond said corresponding iwing section, and means for lockin g. said vertical lifting propellers within their respective recesses when said propellers are in theirpositionsofrest.

3. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the end of each Wing section, said lifting axes from an operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding wing section with the remaining portion thereof extending beyond the wing section, and means for varying the pitch of said vertical lifting propellers so that said lifting propellers can be faired into the adjacent wing surfaces when shifted from said operative position to said position of rest.

' 4. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section, said lifting propellers each being supported to rock about pivotal axes extending transversely of the respective wing sections and the axes of rotation of said lifting propellers, means for rocking said lifting propellers transversely of their axes from an operative position to a position of rest so that a portion of each lifting propeller will be received a recess in its corresponding wing section with the remaining portion thereof extending beyond the Wing section, and means for rotating said lifting propellers in reverse directions when in said operative position, each of said vertical lifting propellers being of a length substantially equal to twice the length of each wing section.

5. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section, said lifting propellers each being supported to rock about pivotal axes extending transversely of the respective wing sections and the axes of rotation of said lifting propellers, means for rocking said lifting propellers transversely of their axes from an operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding wing section with the remaining portion thereof extending beyond the wing section, and means for rotating said vertical lifting propellers in reverse directions when in said operative position, each of said vertical lifting propellers being arranged with respect to its corresponding wing surface when in its inoperative position so that said portion will lie Within the recess and form a substantially uninterrupted streamlined surface for its corresponding wing section.

6. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section, means for rocking said lifting propellers transversely of their axes from an'operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding wing section with the remaining portion thereof extending beyond the wing section, and a cover for each of said recesses to form a substantially continuous streamlined surface for each wing section when the Vertical lifting propellers are arranged for vertical flight.

7. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section,

means for rocking said lifting propellers transversely of their axes from an operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding Wing section with the remaining portion thereof extending beyond the wing section, a movable cover for each of said recesses to form a continuous streamlined surface for each Wing section when the vertical lifting propellers are arranged for vertical flight, and means operable from a position within said aircraft for moving said recess covers to cover and uncover said recesses.

8. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section, means for rocking said lifting propellers transversely of their axes from an operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding wing section with the remaining portion thereof extending beyond the wing section, a cover for each of said recesses to form substantially continuous streamlined Wing surfaces when the vertical lifting propellers are arranged for vertical flight, means operable from within said aircraft for moving said recess covers to and from a position in which said covers form said streamlined wing surfaces, and means projecting into said recesses for locking the nested portion of each vertical propeller therein when said lifting propellers are at rest. a

9. In combination with an aircraft having wing sections, a power plant and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing'section, said propellers being mounted for rocking and swinging movement about ax es at the tips of their respective wing sections extending transversely thereof, means for rocking said lifting propellers transversely of their axes from an operative position to a positionof rest so that a portion of each lifting propeller will be received in a recessin its corresponding wing section with the remaintions when in said operative position, and means for drivingly connecting said propellers to the power plant of said aircraft.

10. In combination with an aircraft having wing sections, a vertical lifting propeller for each wing section having blade portions, said propellers bein'gmounted for rotation about their axes adjacent the ends of the Wing sections and being rockably movable to a position of rest with one of the blades of each of said propellers nested in a recess in its corresponding Wing section and the remaining blade portion of each of said propellers projecting beyond its corresponding wing section. I v

11. In combination with an aircraft having relatively short wing sections, a vertical lifting propeller mounted adjacent the end of each Wing section for rotation about their axes, means for rockably mounting said propellers to swing about axes disposed at right angles to their axes of rotation and transversely of said wing sections, means for rotating said propellers in reverse directions, means for rocking said propellers from an operative position to a position of rest, and means for holding said propellers in said position of rest with portions thereof received in recesses in the wing sections andthe remaining portions projecting beyond and forming extensions of said wing sections.

12. In combination with an aircraft having of rest with a blade portion of each propeller re-V ceived within a recess in its corresponding wing section and the remaining blade portions of said propellers projecting beyond the wing sections to provide continuations of the wing sections, and means for rotating said propellers when in an operating position for vertical lifting flight.

13. In combination with an aircraft having wing sections and a propeller for horizontal flight, a vertical lifting propeller mounted for rotation adjacent the tip of each wing section, said propellers being pivotally supported in rocking movement about axes extending transversely of their respective wing sections, means for rocking said lifting propellers transversely of their axes from an operative position to a position of rest so that a portion of each lifting propeller will be received in a recess in its corresponding wing section with the remaining portion thereof extending beyond the wing section and providing an airfoil surface, a cover for each of said recesses positionable to form a substantially continuous streamlined surface with its adjacent wing surface when the vertical lifting propellers are arranged for vertical flight, means for rotating said propellers, and means operable from a location within the aircraft for controlling the propeller rocking means and said rotating means.

ALEX ISERNA. 

